The way that water is stored and moves on Earth from one place to another and includes evaporation, precipitation, and infiltration.

How does the Hydrologic Cycle work?

First there is evaporation from plants, oceans, and surface water. Clouds then carry the water over the land where precipitation occurs and rain and snow fall over the land and seas. Ice then accumulates over glaciers (mountain tops) which later melts and the froms streams. Infiltration then occurs as the water seeps into the ground and flows into the sea.

What is humidity & in what 3 ways is it expressed?

The measure of how much water vapor is in the air. Expressed as maximum, specific, and relative.

What is maximum humidity?

The maximum amount of water vapor that a body of air can hold

What governs the amount of water vapor that a body of air can hold?

Temperature

Info Card: Warmer air can hold much more water vapor than cold air because air expands as it warms.

What is saturation?

Saturation refers to the point where air cannot hold anymore water vapor based on the temperature at that time.

Info Card: The atmosphere expands with warm air and contacts with cold air.

What is specific humidity?

Refers to how much water vapor is actually in the air.

What is relative humidity?

Refers to the ration of specific humidity to maximum humidity & how close the air is to being saturated.

What is the formula for relative humidity (%)?

(specific/maximum) x 100

What instrument is used to measure humidity?

A sling psychrometer

Info Card: When R.H. is low, the air is relatively low. When R.H. is high, the air is moist and close to being saturated.

What is dew point temperature?

The temperature at which a mass of air becomes saturated (100% R.H.) This is also the point in which condensation will occur. (depends upon the specific humidity)

Info Card: Cooling an unsaturated body of air raises its relative humidity

What happens when air tries to cool below dew point temperature?

Surplus water vapor is removed from the air by the process of condensation.

What is evaporation?

The process of going from liquid water to water vapors

What is transpiration?

The passage pf water from leaf pores to the atmosphere.

What is evapotransporation?

The combined process of evaporation and transpiration; used by geographers when they consider the humidity characteristics of a region.

What does evapotranspiration depend on?

Net radiation (evaporation rates are higher when more energy exist), air temperature (warm air holds more moisture than cold air), and relative humidity (evaporation rates are higher when the air is dry).

Info Card: Water vapor molecules flow from an area of many molecules (close to the water surface) to an area of fewer molecules (further from the surface).

What is the adiabatic process?

Changes in temperature that occur due to variations in air pressure

What is the Dry Adiabatic Lapse Rate (DALR)?

The rate at which unsaturated air cools as it is lifting or warms as it is descending. (5.5 degrees/1000 ft)

What is the Wet Adiabatic Lapse Rate (WALR)?

The rate at which a saturated body of air cools as it lifts. (2.7 degrees/1000 ft)

What is the level of condensation?

The altitude at which water changes from vappor to liquid phase.

What is the environmental lapse rate?

The decrease in temperature that occurs with respect to altitude in the troposphere. (3.5 degrees/1000 ft)

What are clouds?

Visible masses of suspended, minute water droplets or ice crystals.

What 2 conditions are necessary for clouds to form?

The air must be saturated. (cools below the dew point temperature or more water vapor is added) & condensation nuclei must be present.

What are condensation nuclei?

Dust or pollutants that water vapors can condense.

What are the 5 ways in which precipitation can occur?

Rain, freezing rain, snow, sleet, and hail.

What is rain?

Large, unforzen water droplets

What is freezing rain?

Rain that frezes upon impact of hittng the ground which is below the freezing point of water.

What is snow?

Ice crystals that do not melt before reaching the surface

What is hail?

Ice crystals that are continually pulled back up and grow in size during thunderstorms

What is sleet?

Rain that freezes before hitting the ground

How does fog form?

Fog forms when the air at low elevations is saturated with moisture

What is radiation fog?

Fog that develops at night when a temperature immersion exist (meaning a body of cooler air lies beneath a body of warmer air). Usually seen in vallies

What is advection fog?

Fog that develops when warm air flows over a cool surface such as snow or a body of water.

What is sea fog?

Fog that forms when cool marine air comes in direct contact with colder ocean water.

What is rain shadow?

The body of land on the leeward side of a mountain rage that is relatively dry and hot due to adiabatic warming and drying.

Whay is stable air?

A body of air that has a low E.L.R. compared to potential uplifting air, thus convection cannot occur

What is unstable air?

A body of air that has a high E.L.R. compared to potential uplifting air, thus convection can occur.

What is the leeward side?

The side of the mountain that faces away from prevailing winds

What is the windward side?

The side of the mountain that faces prevailing winds

What are the 4 lifting mechanisms?

Convectional, frontal, orographic, and convergant

What is convectional uplift?

Uplift of air that occurs when bubbles of warm air rise within an unstable body of air

What is frontal uplift?

Uplift of air that occurs when contrasting bodies of air collide (ex. warm air with cold air)

What is orographic uplift?

Uplift of air which occurs when air is forced to flow up and over mountains

What is convergant uplift?

Uplift of air which occurs when large bodies of air meet at a central location (ex. winds blowing from the west collide with winds blowing from the east)